Disconnect switch utilizing insulating base having integrally formed insulator bushings

ABSTRACT

A hook disconnect switch having a base member formed of an insulating material and insulator units integrally joined thereto. Two insulators are aligned at an angle relative to one another and support the jaw and pivoting end of a switch blade. The orientation of the insulators significantly reduce cantilever forces imposed by horizontal incoming lines upon the insulators. The base member provides a means for rigidly positioning and supporting the hook switch assembly, as well as enhancing the dielectric strength of the insulators. The design and orientation of the insulators further reduce overall switch size and considerably reduce the effect of contamination for all mounting positions of the switch.

Elnited States Patent Perry et al.

[54] DISCONNECT SWITCH UTILIZING INSULATING BASE HAVING INTEGRALLYFORMED INSULATOR BUSHINGS Feb. 29, 1972 [5 7] ABSTRACT A hook disconnectswitch having a base member formed of an insulating material andinsulator units integrally joined thereto. Two insulators are aligned atan angle relative to one another and support the jaw and pivoting end ofa switch blade. The orientation of the insulators significantly reducecantilever forces imposed by horizontal incoming lines upon theinsulators. The base member provides a means for rigidly positioning andsupporting the hook switch assembly, as well as enhancing the dielectricstrength of the insulators. The design and orientation of the insulatorsfurther reduce overall switch size and considerably reduce the effect ofcontamination for all mounting positions of the switch.

7 Claims, 10 Drawing Figures Patented Feb. 29, 1972 5 Sheets-Sheet 2FIZZ-.44..

Patented Feb. 29, 1972 5 Sheets-Sheet 3 Patented Feb. 29, 1972 5Sheets-Sheet L Patented Feb. 29, 1972 3,646,288

5 Sheets-Sheet 5 DISCONNECT SWITCH UTILIZING INSULATING BASE HAVINGINTEGRALLY FORMED INSULATOR BUSHINGS The present invention relates tohook-operated disconnect switches and more particularly to a novelcompact, one-piece insulator base assembly for hook disconnect switcheshaving angularly oriented insulators with insulator skirts at an angleto the mounting surface and which is designed to obtain maximumself-cleaning of insulator units under rain conditions so as to combatcontaminated atmospheres and to create a novel, pleasing appearance.

Disconnect switches find widespread use throughout the powertransmission and distribution field. One type of disconnect switch,commonly referred to as a distribution switch, is normally provided foruse as a disconnect switch for substation and other applications and isemployed at a variety of distribution voltages and currents anywhere inthe system such as from substation transformer secondaries todistribution transformer primaries. Switches of this type are usuallyemployed in distribution networks in the range from several thousand tomore than 20,000 volts at 200-600 ampere ratings and are typicallymounted out of doors such as, for example, on poles, substations, woodand metal structures, or other suitable supports. The distributionswitch is provided with a hookoperated latching device which normallyrequires the operator to be provided with a long hook stick or polewhich may be inserted into a pull-ring in order to unlatch the blade ofthe switch and separate it from its associated jaw. Such switches aretypically mounted underhung from crossarms on wood poles or onvertically mounted trusses of substation structures, and provided forselective connection or disconnection of load and supply lines connectedto associated equipment. The switch jaw and blade pivoting assembliesare normally supported by end caps provided on insulators which, inturn, are mounted upon a metal baseplate which is electrically insulatedfrom the powerlines connected to the distribution switch pads.

The incoming conductors connected to the switch from the load and sourceends of the system are normally mechanical anchored to grounded parts(base). Therefore, separate suspension insulators must be provided,which insulators are exposed to continuous tensile pull, whilesupporting the lines connected thereto.

The present invention is characterized by providing a distributionswitch of novel design in which the switch supporting insulators-baseunit are combined into an integral unitary member of reduced size,capable to withstand tensile and cantilever forces of incoming lineswith metal parts designed to receive these lines directly without theneed for suspension insulators not heretofore possible in conventionalmountings for distribution switches.

The present invention is comprised of a pair of insulator bushingspreferably integrally formed with a base portion of substantially theinsulating material and having its insulator units aligned at an anglerelative to one another so as to provide increased supporting strengthfor the distribution switch, high resistance to cantilever forcesimposed upon the supporting structure and increased dielectric strengthbeyond that normally provided by conventional supporting insulatorassemblies and to further provide reduced overall structural size anddimensions while retaining all of the other advantages of conventionaldistribution switch supporting assemblies.

It is, therefore, one object of the present invention to provide a novelsupporting assembly for use in connection with distribution switches.

Another object of the present invention is to provide a novel unitaryone-piece supporting assembly for mounting and supporting distributionswitches and having self-cleaning angularly oriented insulator portionsextending from an integral base portion.

Still another object of the present invention is to provide a novelunitary one-piece supporting assembly for positioning and supportingelectrical switches of the distribution type and comprised of acentrally located relatively short base portion having radially alignedinsulator bushing portions for supporting the jaw and blade elements ofa distribution switch wherein the orientation of the insulator bushingportions is such as to provide substantially increased resistance tocantilever forces. The compact switch with short base lends itself formounting on single structural member on low profile substation structureused in more modern design with pleasing appearance and economy.

These as well as other objects of the present invention will becomeapparent when reading the accompanying description and drawings inwhich:

FIG. I is a perspective view showing a typical mounting of a conventionprior art distribution switch and supporting assembly.

FIG. 2 is a perspective view showing a combined insulator and basesupport assembly designed in accordance with the principles of thepresent invention.

FIG. 3 is an elevational view showing the structure of FIG. 2 with adistribution switch mounted thereon.

FIG. 3a shows a sectional view of the assembly of FIG. 3 looking in thedirection of arrows 3a3a'.

FIG. 3b is a sectional view of thejaw section of the switch of FIG. 3looking in the direction of arrows 3b3b'.

FIG. 30 is a sectional view of the blade portion of the switch of FIG. 3looking in the direction of arrows 3c-3c'.

FIG. 4 is an elevational view of a preferred embodiment of the presentinvention employing a distribution switch.

FIG. 4a is a view of the base portion of the apparatus of FIG. 4.

FIGS. 4!) and 4c are typical alternate sectional views of one insulatorof FIG. 4 looking in the direction of arrows 4b4b and 4c-4c,respectively.

Referring now to the drawings, FIG. 1 shows a conventional prior artdistribution switch assembly 10 which is assembled on a pair ofcrossarms M and 12 mounted upon vertical pole 13. A channel-shaped baseassembly 14, preferably formed of steel, is secured to crossarms 11 and12 by means of a pair of channels 15 and 16 of much smallercross-sectional configuration which embrace crossarms l1 and I2therebetween by means of the fastening assemblies 17 (only two of whichare shown in FIG. 1, it being understood that four such fasteningassemblies are provided). The channel-shaped base 14 is provided withsuitable openings (not shown) for securing a pair of insulators withsteel caps 18 and I9 thereto which, in turn, support and have downwardlydepending therefrom a respective pair of insulators 20 and 21. Insulator20 is provided with a jaw assembly 22 which may be selectively latchedwith the end 23a of a blade 23 pivotally mounted at 23b by a suitablesupporting assembly 24 secured to the bottom end of insulator 21. Thesupporting assemblies 22 and 24 are further provided with clampingassemblies 22a and 24 a, respectively, for clamping the ends of anassociated conductors 25 and 26, respectively, which may, for example,be the source and load ends of a powerline in a distribution network.

Since the incoming cables are energized they must be insulated fromground by suspension insulator assemblies designated generally by thenumerals 27 and 30, respectively. Each of the assemblies is providedwith a first end 27a and 3011 which is mechanically coupled to thechannel-shaped base portion 14 so as to be securely anchored thereto.The opposite ends thereof, namely, ends 30b and 27b, are mechanicallycoupled to the ends of incoming cables 25 and 26 whereby the suspensioninsulator assemblies carry substantially the entire supporting loadimparted to the distribution switch base assembly. The connectors 27band 30b are further provided with cable portions 251: and 26a,respectively, for electrically connecting the cables 25 and 26 to thedistribution switch so that the electrical current path extends fromcable 25, extension 25a, jaw 22, blade 23, cable extension 26a and cable26, whereby the insulators 20 and 21, as well as the suspensioninsulators 27 and 30 electrically insulate the high tension lines fromthe base support 14.

FIGS. 2, 3a and 3b show one disconnect switch assembly of the presentinvention which is comprised of a solid unitary insulator assembly 40having a base portion generally designated by the numeral 41 and havinginsulators generally designated by the numerals l2 and 43, respectively.The base portion 41 has a substantially triangular shape comprising abottom section 44 integrally formed with the diagonally aligned sections45 and 46. A vertically aligned supporting rib 47 joins bottom section44 to substantially the apex of the diagonally aligned sections 45 and46 to provide additional rigidity and strength to this unit. The bottomsection 44 is provided with three indentations along one vertical sidethereof and designated by numerals 44a, 44b and 44c (FIG. 30). Each ofthese indentations are adapted to receive a substantially C- shapedmetallic clip such as, for example, the clips 48 and 49 which areprovided for clamping the insulator assembly to a supporting surface.The top and bottom surfaces of each of the clips are provided withsuitable apertures for receiving fastening means 50 and 51,respectively, which may, for exam ple, be bolts passing through suchopenings and having their bottom end portions free to make threadedengagement with a suitable tapped aperture provided either in asupporting plate or in the form of a nut which may cooperate with thebolts 50 and 51 to firmly secure the insulator assembly to thesupporting surface (not shown for purposes of simplicity). It should benoted that indentation 44c is substantially elongated to permit mountingclip 49 to be positioned at any location therealong. Clip 48 may bepositioned so as to have its bolt 50 pass through the cutaway regionformed by surface 44a or may be aligned so as to have its bolt 50 passthrough the open region defined by cutaway portion 44!; therebyproviding a universal arrangement allowing for mountings over rather alarge dimensional span.

The diagonally aligned sections 45 and 46 are each provided withrecesses for receiving the bottom end of any insulator. Only one sucharrangement is shown in FIG. 3 for purposes of simplicityfAs can be seentherein, diagonally aligned section 45 has an opening 52 for receivingand embracing the smaller diameter end portion $30 of insulator 43. Inactuality, the insulators are first produced and are then inserted intoa mold provided for forming the base portion 41 of the assembly. Thesmaller diameter and portions of each insulator protrude into the moldso as to cause the insulating material poured into the mold to surroundand embrace the end cap portion 430 and thereby be integrally joinedthereto. The end cap portion 43a may also be provided with an annularflange 43b for enhancing the supporting strength of the structure.

The insulators may have hollow core (such as, for example, the hollowinterior 43c) and have an undulating exterior surfaceconfiguration 43dto increase creepage distance (which is typical of such insulators). Theopposite smaller diameter end 436 is secured to a disconnect switch jawassembly 53 which is provided with a caplike portion 54 which receivesand embrances the portion 43e of insulator 43. End cap 54 is preferablyrigidly joined to portion 43c of the insulator by means of a suitableadhesive or epoxy which fills the hollow interior space 55 between cap54 and insulator portion 43.

The end cap 54 has integrally joined thereto a terminal portion 55provided with openings 56 for bolting a suitable clamp thereto in orderto join one free end of an incoming conductor (not shown for purposes ofsimplicity). The jaw portion of assembly 53 is further comprised of ablade-engaging portion 58 (note also FIG. 3b) which mechanically andelectrically engages the blade assembly in manner to be more fullydescribed.

The insulator 42 has its upper free end joined to receive a metallic endcap 59 which is further integrally joined to a terminal pad 60 havingopening 61 for securing a terminal clamp thereto in order to join theremaining cable to complete the electrical path through the distributionswitch. A blade pivoting portion 62 is also joined to end cap 59 (noteespecially FIG. 3c) and is provided with a suitable opening 63 forreceiving a fastening assembly comprised of bolt 64, spring washers 65and 66, wedge-shaped members 67 and 68 (for proper distribution ofcontact pressure) and nut 69. This assembly is employed to pivotallymount the blade assembly thereto. The blade assembly is comprised of apair of blade members 70 and which can clearly be seen in FIG. 3c to bepositioned on opposite sides of the blade pivotally mounted section 62.The fastening assembly urges the two portions 70 and 71 of the bladeassembly into good wiping contact with the pivotally mounting portion 62as can best be seen in FIG. 3c. Openings 72 (only one of which is shownin FIG. 3 for purposes of simplicity) are provided for receiving asuitable pin, which, when appropriately positioned, limits the amount ofangular travel which the blade may experience in moving to the openposition. A 90 span between fully closed and fully opened may beobtained by positioning a pin with an opening 72 so as to abut theshoulder 73 provided on blade mounting assembly 62. Removal of a pinfrom the openings 72 permits a larger angular travel, since the blade isthen free to move past shoulder 73 so as to move through a total angleof approximately 135 from the fully closed to the fully open position.

The jaw engaging portion of the switch blade is provided with a latchingassembly mounted between the two blade portions 78 and 71 (note bladeportion 73 has been broken away to expose the latching assembly). Thelatching assembly is comprised of a pin 74 secured between the two bladeportions. A pull ring 75 is provided with a cylindricalshaped projection76 for receiving pin 74 so as to mount the handle between the two bladeportions 70 and 7!. A tortion spring 77 is positioned around thecylindrical projection 76 and has a first end thereof extending throughan opening 78 in pull ring 75 and has a second end thereof resting ingroove 79 of arm 81 of a latching member 80. Pull ring 75 is providedwith an opening 83 for receiving the hook and of a hook stick (notshown) typically employed for opening such distribution switches. Theopposite portion of pull ring 75 is provided with a projection 84 forbearing against arm- 81 of latch member 80.

Latch member (note especially FIGS. 3 and 3b) is provided with anopening 85 for receiving a pin 86 which pivotally mounts the latchmember between the blade portions 70 and 71. Pin 86 has a length greaterthan the distance between blade portions 70 and 71 and is provided witha first clip 87 bearing against the exterior surface of blade portion 70and a second clip 88 provided at its opposite end. A compression spring89 is positioned between exterior surface of blade portion 71 and onesurface of a washer 90 which is positioned just to the left of clip 88so as to cause the compression springs 89 to urge blade portions 70 and71 toward one another and thereby firmly embrace the blade-engagingportion 58 of the jaw assembly.

FIG. 3 shows the distribution switch in the closed position. In thisposition, it can be seen that the hook-shaped arm 91, provided as anintegral part of latch member 80, has its bearing surface 92 positionedimmediately beneath the underside of blade-negaging portion 58. In thisposition (without manipulating pull ring assembly 75) the distributionswitch is latched in the closed position. In order to open thedistribution switch, the hook-shaped end of a hook stick (not shown) isinserted into eyelet 83 to rotate the pull ring assembly 75 clockwiserelative to FIG. 3 as shown by arrow 94. It should be noted that, withthe distribution switch in the closed position, the tortion spring 77prohibits any relative movement between the pull ring assembly 75 andthe latching member 80. By rotating pull ring assembly 75 in theclockwise direction as shown by arrow 94, its lower end projection 84bears against arm ill and acts against the force of tortion spring 77 tourge latching member 80 counterclockwise about itsmounting pin 86 asshown by arrow 95. This causes the bearing portion 92 to be rotated awayfrom the underside of blade-engaging portion 58 enabling thedistribution switch to be moved to the fully opened position. Tortionspring 77 assures that the latching member 80 and handle assembly 75will be retained in their relative positions so as to prevent theprojection 84 from moving out of engagement with the unerside of arm 81.

The terminal pad 57 which forms an integral part of the jaw assembly ofthe distribution switch is further provided with a pair of removableloadbuster attachment hooks 96 and 97 which are shown best in FIGS. 3and 3b and which are provided for use of the switch with a loadbusterdevice.

Terminal pads 57 and 60 are further provided with openings 98 and 99 formechanical anchorage of incoming lines without use of suspensioninsulators now required on conventional switches (plain parallelconnector could be of the type shown in FIG. 1), while connecting cableextensions of the type shown in FIG. 1 directly to the terminal pads 57and 60 through suitable terminal clamps (not shown) which are fastenedby means of fastening members (not shown) and bolt holes 56 and 61respectively to clamp the cable extensions thereto in applications wherethis becomes necessary.

FIG. 4 shows an alternative embodiment for a distribution switchassembly in which like elements have been designated with like butprimed numerals. In the embodiment of FIG. 4, the insulator and baseassembly is comprised of insulators 42' and 43' which are integrallymolded in a single operation with base portion 41'. The base portion isof a different configuration from that shown in FIG. 3 and is providedwith openings 101 and 102 which cooperate with the side openings 44a and440' along one edge of base portion 41 (see FIG. 4a) to receive theclamping assemblies 48' and 49' having bolts 50 and 51 respectively,forjoining the unitary assembly to a supporting surface in the samemanner as was previously described. The insulators 42' and 43 are eachangularly aligned relative to the plane of the bottom edge of baseportion 41'. Typical cross-sectional configurations of the unit 43 areshown in FIGS. 4b and 4c.

The upper ends of the insulators 42 and 43 are mounted to end caps 54'and 59' in a manner similar to that shown in FIG. 3. The disconnectswitch assembly is substantially similar to that shown in FIG. 3 exceptthat the terminal pads 57' and 60' are substantially coplanar with theplane of the base portion 41'. The disconnect switch assembly inoperation is also substantially similar to that shown in FIG. 3.However, the increased supporting strength and the high resistance tocantilever forces which the assembly of FIG. 4 is able to withstand,totally eliminates the need for suspension insulators as has beendescribed hereinabove.

It can therefore be seen from the foregoing description that the presentinvention provides a novel combined insulator and base supportingassembly for use in mounting and supporting disconnect switches in whichthe angular orientation of the insulator members in outdoor mountingprovides under effect of rain self cleaning removal of contamination andoffers high resistance to cantilever forces and a smaller overall sizewhile retaining all of the advantages of conventional disconnect switchinsulator support assemblies.

Although there has been described a preferred embodiment of this novelinvention, many variations and modifications will now be apparent tothose skilled in the art. Therefore, this invention is to be limited,not by the specific disclosure herein, but only by the appending claims.

We claim:

I. An integral one-piece insulation support assembly for distributionswitches and the like comprising a base portion having a substantiallyplanar mounting surface;

fastening means embracing said base portion forjoining said assembly toa supporting surface;

first and second elongated insulators having their first ends integrallyjoined to and supported by said base portion on the side opposite saidmounting surface and extending radially outward from said base portion,said insulators being diagonally aligned relative to said mountingsurface, said base and said insulators being formed as an integralmolded unit and being comprised of the same insulating material.

2. The assembly of claim 1 wherein the angular alignment of theinsulators is substantially a right angle.

3. The assembly of claim 1 wherein said insulators and base portion areformed of an insulating material, said material bein orcelain, epox orcombination of both. I

4. e assembly 0 claim 1 further comprising a switch assembly having ablade and ajaw portion;

said jaw portion including an end cap mounted on the second end of oneof said insulators;

said blade portion including an end cap mounted on the second end of theremaining one of said insulators;

a blade;

mounting means for pivotally mounting one end of said blade to saidblade portion end cap whereby said blade is adapted to have its oppositeend engage said jaw portion when said blade is pivoted to the closedposition.

5. The assembly of claim I wherein each of said insulators is providedwith skirts aligned transverse to the mounting sur face to provide forself-cleaning of contamination deposits thereon.

6 The assembly of claim 4 further comprising first and second terminalpads electrically connected to said jaw and blade portion end capsrespectively;

means for mechanically securing and electrically connecting cableterminals to said pads for coupling said switch into an electricalcircuit.

7. The assembly of claim 4 further comprising pull ring operated latchmeans pivotally mounted to said blade and engaging said jaw portion forlatching said blade in said closed position and being movable in a firstdirection for unlatching said blade from said jaw portion.

1. An integral one-piece insulation support assembly for distributionswitches and the like comprising a base portion having a substantiallyplanar mounting surface; fastening means embracing said base portion forjoining said assembly to a supporting surface; first and secondelongated insulators having their first ends integrally joined to andsupported by said base portion on the side opposite said mountingsurface and extending radially outward from said base portion, saidinsulators being diagonally aligned relative to said mounting surface,said base and said insulators being formed as an integral molded unitand being comprised of the same insulating material.
 2. The assembly ofclaim 1 wherein the angular alignment of the insulators is substantiallya right angle.
 3. The assembly of claim 1 wherein said insulators andbase portion are formed of an insulating material, said material beingporcelain, epoxy or combination of both.
 4. The assembly of claim 1further comprising a switch assembly having a blade and a jaw portion;said jaw portion including an end cap mounted on the second end of oneof said insulators; said blade portion including an end cap mounted onthe second end of the remaining one of said insulators; a blade;mounting means for pivotally mounting one end of said blade to saidblade portion end cap whereby said blade is adapted to have its oppositeend engage said jaw portion when said blade is pivoted to the closedposition.
 5. The assembly of claim 1 wherein each of said insulators isprovided with skirts aligned transverse to the mounting surface toprovide for self-cleaning of contamination deposits thereon.
 6. Theassembly of claim 4 further comprising first and second terminal padselectrically connected to said jaw and blade portion end capsrespectively; means for mechanically securing and electricallyconnecting cable terminals to said pads for coupling said switch into anelectrical circuit.
 7. The assembly of claim 4 further comprising pullring operated latch means pivotally mounted to said blade and engagingsaid jaw poRtion for latching said blade in said closed position andbeing movable in a first direction for unlatching said blade from saidjaw portion.